German Zeppelins of WWI

Commanded by the 33-year-old airship ace Heinrich Mathy, it was one of a new generation of super-Zeppelins designed to overpower the increasingly sophisticated British air-defences.

A master navigator and aerial tactician, Mathy was a veteran of numerous raids, during which he had acquired a reputation for cool determination and daring. But something of the old confidence had gone. He was the sole survivor among a core group of veteran commanders in a highly specialised service. The tight-knit military elite of which he was the leading representative had recently been shaken by heavy losses.

When history’s first strategic bombing campaign had begun early in 1915, the giant airships had come and gone with impunity.

Later, there had been occasional losses to accidents and enemy fire. Then, suddenly, just a week before, on the night of 23-24 September, two of the new super-Zeppelins had been shot down. One of them had turned into a raging fireball which plunged to earth killing all on board. The horror had been visible to the rest of the airship fleet strung out across the skies over southern Britain.

The event had shattered the nerves of the German airship crews, and many were showing signs of combat fatigue.

Among Mathy’s crew, the mess-room mood was sombre. There was much talk of the losses. Men slept uneasily, haunted by bad dreams and visions of falling airships. Even Mathy was on edge. Though he endeavoured to behave as normal, his men noticed the change: his appearance more serious, his features more sharply and deeply graven in his face. And in the privacy of his quarters, he confessed his fears in a letter to his young wife, at home nursing a new baby: ‘Peterson is dead, Böcker a prisoner. Hertha, the war is becoming a serious matter… During these days, when you lay our little daughter down to sleep, a good angel will see you and will read what is in your heart, and he will hasten to guard my ship against the dangers which throng the air everywhere about her.’ But a week later, he was dead.

Mathy’s airship was a giant cigar-shaped cylinder of gas bubbles filled with highly flammable hydrogen. It flew only because it was lighter than air. A huge lightweight framework of duralumin girders and steel wires supported a row of 19 gas-bags made of animal membrane, cotton fabric, and glue, which, when inflated, contained two million cubic feet of gas and filled almost the entire internal space.

Stretched over the exterior of the framework was an envelope of light cotton fabric, coated in dope, laced together, and pulled taut. The keel of the duralumin framework formed a gangway running the length of the ship, and here were stowed water-ballast sacks, petrol tanks, and bomb racks. Slung beneath the keel were the forward control gondola and three engine gondolas, a large one towards the rear, two smaller ones amidships.

The airship’s six engines, which powered an array of six propellers, one at the back of each gondola, and two suspended directly beneath the hull, afforded a maximum speed of 63mph. Direction was controlled by cables which ran from the forward gondola to movable rudders and elevators attached to the ends of the four tail-fins. A triumph of German engineering, at almost 200m long and 24m across, L31 was bigger than a battleship.

The crew of an airship were all volunteers. Around 20 in total, half were machinists serving the engines, which required constant maintenance and occasional in-flight repairs. Though warmed by the engines during the long hours of flight, the machinists were assailed by a head-splitting roar and an asphyxiating mix of oil and exhaust fumes.

In the control car, on the other hand, the commander, the executive officer, the navigator, two petty officers operating rudders and elevators, and two more working in the soundproof wireless compartment, all endured extremes of cold. Even in summer, temperatures could sink below -25°C. At high altitudes, airship crew wore thick woollen underwear, blue naval uniforms, leather overalls, fur overcoats, scarves, goggles, leather helmets, thick gloves of leather and wool, and large felt overshoes covering their boots. They were sustained by generous rations of bread, sausage, stew, chocolate, and thermos flasks of strong coffee.

Thus did the pioneers of military aviation enter the strange new combat zone of the upper skies. The technology was unreliable. The risks were high. The wartime casualty rate among German airship crew was 40%. And two and a half miles up, there were special terrors not faced by men on the ground. There was nowhere to run to, no way of escape; one lived or died as the machine flew or crashed. Men perished in the airships because engines failed, or storms blew up, or commanders simply lost their way and ran out of fuel.

On the morning of 2 February 1916, the crew of L19 were seen clinging to the wreckage of their airship by a British trawler captain 110 miles east of the Yorkshire coast. He refused to rescue them, fearful they might seize his vessel, and they were left to be consumed by the cold wastes of the North Sea. Six months later, a message in a bottle washed up on the Swedish coast was found to contain

the German commander’s last official report.

Above all, airship crew feared being set on fire, either in the air or trapped in a tangle of flaming wreckage on the ground. In the mess-rooms, they debated whether or not, if their airship was shot down, to jump at the last minute. The impact of those who did sometimes left macabre imprints in the ground.

The defences around London – searchlights, anti-aircraft guns, and home-defence fighter squadrons – had thickened alarmingly. Individually, neither guns nor planes were a serious threat. It was estimated after the war that only one in 8,000 of the anti-aircraft shells fired scored a hit, and that around 90% of home-defence pilots never so much as saw their enemy. But en masse, a network of lights, guns and planes, if sufficiently dense, could create a zone of lethal danger over the British capital.

By the early autumn of 1916, such a system was in place. Rings of lights and guns were activated without hesitation and at long range. Once enemy raiders were spotted, they were liable, on a clear night, to be held in a pyramid of light-rays and targeted by numerous 3-inch quick-firing anti-aircraft guns, some in fixed positions, others moved around on lorries. Firing 15 rounds a minute to a maximum vertical range of 18,000 feet, the guns were able to fill the sky with enough bursting shrapnel to keep the raiders hovering on the fringes of the capital – the killing zone of the British fighters.

The staple of the home-defence squadrons was the BE2c biplane. Its main advantage was exceptional stability, which made it especially suitable for the hazardous landings of night-flying missions. But it was painfully slow: maximum speed was under 75mph, and it took more than half an hour to climb to its ceiling of 10,000 feet. There was therefore only one effective way to operate. At each station, the on-duty pilot would wait by his machine for an air-raid warning and the order to scramble. He would then ascend onto a regular patrol line for his three-hour stint in the air. If, however, he sighted an enemy raider, his standing orders were to pursue and attack.

The British had already developed a distinctive air-war doctrine: air supremacy – and thereby security from aerial observation and bombardment – was to be achieved by relentless efforts to locate and destroy enemy aircraft. The British fighters were hunter-killers. The handful of young officer-pilots who flew them – rising alone in open cockpits into the freezing night air – formed the deadly cutting-edge of a home-defence system that now employed 17,000 men.

As the Zeppelins hummed towards Britain, remote listening stations picked up their radio messages, and patrol ships and coastal observation-posts watched for them in the sky. Early warnings were phoned to Room 40 at the Admiralty in London, and from there the message went out ‘Take air raid action’. Lights snapped on, guns were made ready, and aircraft at a dozen airfields coughed into life and were sent bumping across the grass for take-off.

Despite the danger, Heinrich Mathy in L31 remained determined to penetrate the defences and bomb the enemy capital. After making landfall near Lowestoft at 9.00pm, he headed south-west for London. But the threat of converging searchlights caused him to sheer away northwards again at around 10.45pm.

Only now were the home-defence pilots getting onto their patrol lines. Mathy circled for a time, then throttled his engines and attempted to cross the northern gun defences by drifting silently with the wind, hoping to remain undetected. But when he reopened his engines at 12.30am, lights and guns burst into life, and the commotion attracted the attention of the fighters, now prowling for prey along the furthest edges of the capital.

Second Lieutenant Wulfstan Tempest saw a small cigar-shaped object illuminated by a pyramid of seachlights and bracketed by exploding shrapnel: Mathy’s Zeppelin. As the BE2c fighter raced towards it, L31 turned sharply away, jettisoned its bombs, and began climbing steeply.

Mathy was not fast enough. Though forced to hand-operate a broken fuel-pump, Tempest closed the gap and dived on the rising airship. Two miles up in the blackness of the night, a new kind of combat was fought, as a tiny single-manned aeroplane of wood, fabric and glue, its only armament a light machine-gun, sped towards a giant of the air 25 times bigger.

Tempest fired first as he dived, then again as he flew beneath the monster. No effect. He next banked his plane and came in once more beneath the tail. Flying under the airship’s hull, he opened fire for the third time, raking the length of it with bullets. At first he despaired when again nothing seemed to happen, and then ‘I saw her begin to go red inside like an enormous Chinese lantern.’

That autumn, the British pilots deployed a new weapon. No longer dependent on dropping bombs or explosive darts over the side, nor on the standard machine-gun ammunition that appeared to have no effect whatever on the giant gas-bags, the home-defence squadrons now filled their ammunition belts with a mixture of tracer and newly-designed explosive and incendiary bullets. The idea was to blow a hole in the fabric of an airship and then ignite the escaping hydrogen as it mixed with air. The new weapon had claimed three airships in a month. Now it claimed a fourth.

Mathy’s Zeppelin shot 200 feet upwards, hung in the air for a moment, and then began to fall. Gas cells exploded into incandescent fireballs. Sheets of envelope fabric were ripped off and blasted into the night sky. Flames streaked up the sides and the airship became an immense torch, glowing orange, yellow and white, hissing and roaring as it plunged earthwards.

Tempest only narrowly escaped the inferno. He was forced to nosedive, put his machine into a spin, and corkscrew his way clear. It left him feeling sick and disoriented. When he eventually picked out the night flares of an airfield runway, he misjudged his height in the fog and crashed, losing his undercarriage and clunking his head on the butt of his Lewis gun. He was lucky to suffer nothing worse than a cut and a headache; landing crashes accounted for most of the 28 fighter pilots killed in the air war over Britain.

The remains of L31 landed in a field at Potters Bar, about 10 miles north of London. All the crew were killed, most of them burnt in the wreckage, though one had jumped and was found half-embedded in the soil, apparently still breathing when first seen: the German airship-ace himself.

The disaster had been witnessed across London the night before. Spontaneous cheering and applause had filled the streets. Now huge crowds gathered at the wreck site to bear witness to the British victory. Three of the new super-Zeppelins, each commanded by a veteran captain, had been shot down. It was the turning-point in the air war: the British had defeated the world’s first strategic bombing campaign.